The parts themself should be around 60.00 each. Labor is the rest. It is an involved job, and requires special tools. Removing the coil spring from the assembly can be dangerous if you don't know how to do it or have the proper tools.

Also, after replacement, I recommend having an alignment. The strut is what actually adjust the camber which is one of the three adjustments made for alignment. When the strut is removed, unless it is marked, the camber is usually bad. As a result, you'll wear tires on the inside or outside.